PLANKTON-TYPES. DESMO-PLANKTON. 



23 



Limits 



Phalcroma cuneus 3° S.- 



P. doryphorum 12° S.- 



P. Hindmarchii 9°N.- 



P. rapa 20° S.- 



P. operculatum 17° S.- 



Podolampas bipes 16° S.- 



P. palmipes 20° S.- 



Pyrophacus horologium .. 20° S.- 



Steiniella mitra 7°N.- 



Pyrocystis fusiformis 29° S.- 



P. pseudonoctiluca 25° S.- 



Asterolampra marylandica 9°N.- 



A. rotula 21° S.- 



Chsetoceros peruvianus... 21° S.- 



C. coarctatus 25° S.- 



C. tetrastichon 10°N.- 



Climacodium biconcavum 26° S.- 



C. Frauenfeldianum 12° S.- 



Hemiaulus Hauckii 24° S.- 



H. Heibergii ' 6° N.- 



Rhizosolenia acuminata.. 35° S.- 



R. Castracanei 35° S.- 



TrichodesmiumThiebauItii 26° S.- 



-40° N. 

 -57° N. 

 -34° N. 

 -42° N. 

 -47° N. 

 -53° N. 

 -68° N. 

 -66° N. 

 -42°N. 

 -44° N. 

 -40°(60)N. 

 -36° N. 

 -39° N. 

 -48° N. 

 -47° N. 

 -46° N. 

 -42° N. 

 -42° N. 

 -45° N. 

 -26° N. 

 -40° N. 

 -48° N. 

 -59° N. 



Mean 

 tempe- 

 rature 



22 7 

 22.0 

 24.2 

 21.1 

 22.4 

 23.0 



19.2 



23.5 

 22.2 



21.5 

 23.88 



24.4 

 27.0 



21.6 



23.4 

 23.1 



24.5 

 25.4 

 23.4 

 24.8 

 23.6 

 20.1 

 24.5 



Mean 

 salinity 



36.49 

 35.96 

 36.27 



35.80 



36.23 

 35.74 

 25.69 

 35.79 

 35 82 



35.40 



35.93 



36 19 



36.68 



36.05 

 35.01 

 36.18 

 35.81 

 35.21 



36.66 



36.01 

 35,13 



35.87 

 35.46 



Outside 



tlio 

 Atlantic 



M. I. 

 M. R. I. 



South P. 

 M. R. I. 

 M. R. I P. 

 M. R. I. P. 

 M. I. P. 

 M. 



R. I. P. 



R. I. 



I. 



M. R. I. P. 



I. 



M. 



M. R. 



R. 1. P. 



M. I. P. 



M. R. I. P. 



M. P. 



M. 



M. I. 



It appears from the above Jist that the animal plankton is re- 

 presented by a considerable number of copepoda, tintinnodea and 

 radiolaria. The phytoplankton is poor in diatoms, in respect to both 

 the number of species and the number of individuals, the bulk of it 

 being represented by Trichodesmrum, Pyrocystis and various dino- 

 flagellates. 



Most of the species of the Desmo-plankton go far to the south 

 and as a rule to 40° or 50° N. Nevertheless, some species may 

 occasionally and as rare specimens drift together with the Styli- 

 lankton still farther northwards, or to about 60° N. Most of thed 

 species of the Desmo-plankton occur besides in the Mediterranean, 

 many of them also in the Pacific and the Indian Ocean. 



